Retinal ganglion cells (RGCs) are the output cells of the retina, and RGC computation is the last processing step before visual information is sent to the brain. RGCs are among the best understood early sensory neurons in terms of their anatomy, physiology and computational properties, yet the manner in which RGCs encode visual information under natural viewing conditions is virtually unexplored. The goal of this project is to begin to bridge the gap between RGC physiology and natural function in the primate retina. Identifying the computations performed by RGCs during natural viewing will form a more complete understanding of sensory computation in the retina. Moreover, studying RGC function during natural viewing is necessary in order to restore visual function after retinal disease using prosthetic devices. It is crucial to capture as much relevant information in the visual world as possible and encode it in a way that is useful for the brain. Therefore it is essential to understand what features of the natural visual world RGCs are encoding, and how this encoding is achieved by the retina. After many decades of investigation using simple, arti?cial visual stimuli (e.g. bars, spots, and ?ickering patterns), a great deal is known abou how RGCs process visual information over space. The spatial receptive ?eld (RF) describes the manner in which input is integrated over visual space to produce RGC responses. This project will describe how the structure of the spatial RF arises from retinal circuitry and how RF structure in?uences RGC sensitivity to features of natural retinal inputs, including ?ne spatia detail and the motion of the retinal image due to eye movements. In this training fellowship, the applicant will use electrophysiological recording techniques in an in vitro primate retinal preparation while presenting visual stimuli, including natural retinal inputs that incorporate real eye movements, to connect RF structure to RGC function in the context of natural viewing.